Personal loan is to pay for balaance of depost AND government charges. (VIC so massive stamp duty + the rest)
Depending on deposit size (assuming less than 20%) you probably get stung with LMI
In any circumstance you will be lending at the maximum equity of the property so there is no room to refinance the personal loan into the home loan for a good 3+ years. There is also no opportunity to refi any credit cards or existing loans to reduce monthly commitment.
In short you will likely end up paying high rates on a mortgage that is most likely from a 2nd tier lender in addition to LMI and a huge personal loan with massive monthly commitments (+ any other existing lending) for at least 3 years until you finally refinance to a decent product if you don't go broke first.
Oh and if it doesn't work out and you want to sell, you will have a terrible time because you will be too highly geared and remain stuck